Pleated filter assembly

ABSTRACT

A filter assembly comprising an outer housing having upstream and downstream openings to permit fluid flow therethrough, an inner housing having an upstream and downstream opening therein to permit fluid flow therethrough, the inner housing being adapted for being received by the outer housing, and a pleated filter medium disposed transverse the direction of fluid flow between the upstream and downstream openings, the pleated filter being adapted to be received by the inner housing.

United States Patent [191 McAllister PLEATED FILTER ASSEMBLY [75]Inventor: Robert L. McAllister, Louisville, Ky.

[73] Assignee: American Air Filter Company, 1nc.,

Louisville, Ky.

[22] Filed: May 19, 1972 [21] Appl. No.: 254,873

[52] US. Cl 55/481, 55/499, 55/514, 55/521, 55/528, 210/493 [51] Int.Cl. B0111 27/06 [58] Field of Search 55/496-500, 478-481, 55/521, 514,528; 210/493 [56] References Cited UNITED STATES PATENTS 1,220,8883/1917 Porter 55/500 1,832,281 11/1931 Davies 55/497 3,246,456 4/1966Sharp 55/500 1 Feb. 26, 1974 3,246,457 4/1966 DeBaun 55/521 3,494,1132/1970 Kinney 55/497 FOREIGN PATENTS OR APPLlCATlONS 1,229,579 3/1960France 55/497 Primary ExaminerBernard Nozick [57] ABSTRACT A filterassembly comprising an outer housing having upstream and downstreamopenings to permit fluid flow therethrough, an inner housing having anupstream and downstream opening therein to permit fluid flowtherethrough, the inner housing being adapted for being received by theouter housing, and a pleated filter medium disposed transverse thedirection of fluid flow between the upstream and down stream openings,the pleated filter being adapted to be received by the inner housing.

3 Claims, 2 Drawing Figures PLEATED FILTER ASSEMBLY BACKGROUND OF THEINVENTION The present invention relates to fluid filters. In one aspect,it relates to a filter assembly utilizing pleated filter media. Inanother aspect, the invention relates to a pleated filter assemblyincluding means for easy removal and replacement of pleated filtermedia.

In air filtration systems which are installed in office buildings,industrial plants, and particularly in residences, replaceable typefilters have been utilized. For many years, filters utilizing non-wovenfibrous material, such as non-woven fiberglas, as a filtering media havebeen used in these air filtration systems for removing undesirableparticles from the air. The filters presently in use come in many sizesand shapes and are constructed by many different methods, but the mostcommon type of filters in use today is one in which a basic core ofloosely packed glass fibers bound together by a resinous coating isconfined between two closely perforated sheets of brass. However, theefficiency of these filters is of a relatively low order.

SUMMARY'OF THE INVENTION In the present invention, it is recognized thatit is desirable to provide a filter which is inexpensive but yet durablein present air filtering systems. Furthermore, it is recognized that itis desirable to provide a filter which is easily constructed withimproved efficiency for use in residential air filtering systems.

The present invention advantageously provides a straightforwardarrangement for a pleated filter assembly. The present invention furtherprovides a filter assembly which is relatively inexpensive to installand maintain. The present invention even further provides a pleatedfilter assembly wherein the media is easily replaced and has an improvedfilter efficiency in residential air filtering systems.

Various other features of the present invention will become obvious tothose skilled in the art upon reading the disclosure set forthhereinafter.

More particularly, the present invention provides a pleated filterassembly comprising an outer housing having an outer border framedefining an open upstream and downstream end to permit fluid flowtherethrough; an inner housing having an inner border frame memberdefining an open upstream and downstream end to permit fluid flowtherethrough, the inner housing being adaptable to be received by andwithin the outer housing; and, a pleated filter medium disposedtransverse the direction of the fluid flow between the upstream and thedownstream ends, the pleated filter medium being adapted to be receivedby the inner housing.

It is to be understood that the description of the present inventiongiven hereinafter are not by way of limitation and various modificationswithin the scope of the present invention will occur to those skilled inthe art upon reading the disclosure set forth hereinafter.

Referring to the drawing:

FIG. 1 is an exploded perspective view of the filter assembly of thepresent invention;

FIG. 2 is an enlarged perspective view of the filter media included inthe filter assembly of FIG. 1.

FIG. 1 of the drawing illustrates an exploded structure of a filterassembly of the present invention. The

filter assembly in the illustration includes an outer housing 1 havingan upstream flow-through opening 2 therein with flanged portion 25extending inwardly along the periphery thereof and a downstreamflowthrough opening 3 therein with flanged portion 26 extending inwardlyalong the periphery thereof. A second or inner housing is provided andincludes border frame members 4 and 5, border frame member 4 having anupstream air opening 7 and a downstream air opening 6 therein withinwardly extending flange 21 disposed along the periphery of the opening6, and border frame member 5 having an upstream air opening 9 withinwardly extending flange 22 disposed along the periphery of the opening9 and a downstream air opening 8 therein. Border frame member 4 has anouter periphery of generally the same size and shape as the innerperiphery of the border frame member 5 wherein border frame 4 will matewithin border frame member 5 in a telescoping relationship. Disposedwithin the inner housing and in communication with the border frame 4 isa pleated filter media 10, the pleated filter media 10 being formed fromany suitable filter material known in the art, one preferred filtermaterial being non-woven cotton linters of generally about 4 inch toabout /1 inch in thickness with a backing of cheesecloth, netting, orthe like. It is realized that the inner housing may be of unitaryconstruction and include only border frame member 4 instead of theexample which illustrates border frame members 4 and 5 mating intelescoping relation. However, for disposition of a filter assembly in avertically extending air passageway, an inner housing including borderframe members 4 and 5 is preferred since border frame member 4 includinginwardly extending flange 21 along the periphery of the downstream airopening 6 and border frame member 5 including an inwardly extendingflange 22 along the periphery of the upstream air opening 9 maintain thefilter media 10 in place in the inner housing during insertion of theinner housing into an outer housing disposed in the vertically extendingair passageway.

The pleated filter media 10 may also be collapsible into a small packagefor shipment. As can be seen in FIG. 2 of the drawing, for packaging,the filter media 10 of the high efficiency particulate air filter typeis laminated to a corrugated support grid 12 which may be formed from,for example, a suitable stiff cardboard material, the cardboard gridhaving interior trans versely extending support portions 15. Thecorrugated grid 12 may be folded, for example, along the transversesupport portions 15 to a compact state for inserting into box 16 forshipment.

The border frame 4 which receives the filter media 10 therein includes araised spacing portion 14 disposed along the inner wall of side 18 ofthe frame 4, spacing portion 14 extending transversely across the framein a zig-zag configuration whereby media 10 being bent along corrugatedgrid 12 at support portions 15, as described above, is positionedwithinthe border frame member in zig-zag communication with the spacingportion 14 thereby maintaining the media 10 in a pleated and supportedcondition when in operation. Spacing portion 14 is illustrated as araised rib member attached to the wall 18 by any known means, such asgluing, soldering, riveting, or the like. The raised rib member asillustrated is a die cut corrugated cardboard, cut in a preselectedzig-zag configuration, but may be of other construction, such as moldedpolystyrene beads. Further, the raised spacing portion 14 may be anintegral part of the frame member 6 if so desired. It is realized that asecond raised spacing portion may be utilized along the inner wall ofside 19, the spacing portion (not shown) extending transversely in azig-zag configuration across the inner wall of side 19 in cooperationwith the spacing portion 14 to hold the pleated filter media 10 in apredetermined zig-zag configuration.

Outer housing 1 further includes a pivotally mounted side member 17which when pivoted outwardly leaves an opening of a sufficient size toreceive inner housing border frame including border frame 4 and filtermedia therethrough. Side member 17 also includes locking means, such as,tongue 23 and mating groove 24 for securing inner housing, including thefilter media 10, in place during operation.

In the preparation of the filter assembly of the present invention, apleated filter media 10 is inserted into border frame member 4 whereinsupport grid 12 is aligned with spacer portion 14 of wall 18. Innerborder frame member 4 is then slidably mounted in telescopingrelationship within border frame member 5, inwardly extending flange 21along the periphery of the downstream opening 6 and inwardly extendingflange 22 along the periphery of the upstream air opening 9 holdingfilter media 10 in place. Side member 17 is then pivoted into a positionto allow the insertion of the inner housing including filter media 10therein into the outer housing 1.

In order to replace a filter 10 whenever it becomes dirty or cloggedwith solid particulate matter, all that is necessary is to open the sidemember or door 17, remove the inner housing including the filter media10 and slidably remove the inner border frame 4 from the inner borderframe 5, remove the dirty filter 10, replace with a clean filter media10, and reverse the aforementioned procedure and replace in the outerhousing 1.

It will be realized that various changes may be made to the specificembodiment shown and described without departing from the principles ofthe present invention.

What is claimed is:

l. A pleated filter assembly comprising: an outer housing including anouter border frame member defining an open upstream and downstream endto permit fluid flow therethrough; an inner housing having an innerborder frame member defining an open upstream and downstream end topermit fluid flow therethrough,

said inner housing including a flow-through outer border frame member,said border frame members mating in a removably detachable telescopingrelationship, said outer border frame member having an inwardlyextending flange along the periphery of an outer end, said inner borderframe member including four sides with a raised rib member of apreselected zig-zag configuration along at least one of said sidesthereof aligning with and supporting a pleated filter medium in azig-zag configuration, said pleated filter medium including a corrugatedsupport grid having transversely extending support portions, saidsupport grid being bent along said transversely extending supportportions to form a support grid of zig-zag configuration, said innerhousing being removably disposed within said outer housing, said pleatedfilter medium being disposed transverse the direction of the fluid flowbetween said upstream and downstream ends of said inner housing.

2. The pleated filter assembly of claim 1 wherein said outer housingincludes a pivotably mounted side member therein for receiving saidinner housing therethrough.

3. A pleated air filter assembly for use in a vertically extending airpassageway, said assembly comprising: an outer housing including anouter border frame member defining an open upstream and downstream endto permit fluid flow therethrough; an inner housing having an innerborder frame member defining an open upstream and downstream end topermit fluid flow therethough, said inner housing including aflow-through inner border frame member and a flow-through outer borderframe member, said border frame members mating in a removably detachabletelescoping relationship, said outer border frame member having aninwardly extending flange along the periphery of an outer end, saidinner border frame member including four sides with a raised rib memberof a preselected zig-zag configuration along at least one of said sidesthereof aligning with and supporting a pleated filter medium in azig-zag configuration, said pleated filter medium including a corrugatedsupport grid having transversely extending support portions, saidsupport grid being bent along said transversely extending supportportions to form a support grid of zig-zag configuration, said innerhousing being removably disposed within said outer housing, said pleatedfilter medium being disposed transverse the direction of the fluid flowbetween said upstream and downstream ends of said inner housing.

1. A pleated filter assembly comprising: an outer housing including anouter border frame member defining an open upstream and downstream endto permit fluid flow therethrough; an inner housing having an innerborder frame member defining an open upstream and downstream end topermit fluid flow therethrough, said inner housing including aflow-through outer border frame member, said border frame members matingin a removably detachable telescoping relationship, said outer borderframe member having an inwardly extending flange along the periphery ofan outer end, said inner border frame member including four sides with araised rib member of a preselected zig-zag configuration along at leastone of said sides thereof aligning with and supporting a pleated filtermedium in a zig-zag configuration, said pleated filter medium includinga corrugated support grid having transversely extending supportportions, said support grid being bent along said transversely extendingsupport portions to form a support grid of zig-zag configuration, saidinner housing being removably disposed within said outer housing, saidpleated filter medium being disposed transverse the direction of thefluid flow between said upstream and downstream ends of said innerhousing.
 2. The pleated filter assembly of claim 1 wherein said outerhousing includes a pivotably mounted side member therein for receivingsaid inner housing therethrough.
 3. A pleated air filter assembly foruse in a vertically extending air passageway, said assembly comprising:an outer housing including an outer border frame member defining an openupstream and downstream end to permit fluid flow therethrough; an innerhousing having an inner border frame member defining an open upstreamand downstream end to permit fluid flow therethough, said inner housingincluding a flow-through inner border frame member and a flow-throughouter border frame member, said border frame members mating in aremovably detachable telescoping relationship, said outer border framemember having an inwardly extending flange along the periphery of anouter end, said inner border frame member including four sides with araised rib member of a preselected zig-zag configuration along at leastone of said sides thereof aligning with and supporting a pleated filtermedium in a zig-zag configuration, said pleated filter medium includinga corrugated support grid having transversely extending supportportions, said support grid being bent along said transversely extendingsupport portions to form a support grid of zig-zag configuration, saidinner housing being removably disposed within said outer housing, saidpleated filter medium being disposed transverse the direction of thefluid flow between said upstream and downstream ends of said innerhousing.